Seo Jooyeok, Park Soohyeong, Song Myeonghun, Jeong Jaehoon, Lee Chulyeon, Kim Hwajeong, Kim Youngkyoo
Organic Nanoelectronics Laboratory and KNU Institute for Nanophotonics Applications (KINPA), Department of Chemical Engineering, School of Applied Chemical Engineering, Kyungpook National University, Daegu 41566, Korea.
Advanced Composites Materials Technical Center, Toray Advanced Materials Korea, Gumi-Si, Gyeongbook 39422, Korea.
Molecules. 2017 Feb 9;22(2):262. doi: 10.3390/molecules22020262.
We report the effect of weak base addition to acidic polymer hole-collecting layers in normal-type polymer:fullerene solar cells. Varying amounts of the weak base aniline (AN) were added to solutions of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). The acidity of the aniline-added PEDOT:PSS solutions gradually decreased from pH = 1.74 (AN = 0 mol% ) to pH = 4.24 (AN = 1.8 mol %). The electrical conductivity of the PEDOT:PSS-AN films did not change much with the pH value, while the ratio of conductivity between out-of-plane and in-plane directions was dependent on the pH of solutions. The highest power conversion efficiency (PCE) was obtained at pH = 2.52, even though all devices with the PEDOT:PSS-AN layers exhibited better PCE than those with the pristine PEDOT:PSS layers. Atomic force microscopy investigation revealed that the size of PEDOT:PSS domains became smaller as the pH increased. The stability test for 100 h illumination under one sun condition disclosed that the PCE decay was relatively slower for the devices with the PEDOT:PSS-AN layers than for those with pristine PEDOT:PSS layers.
富勒烯太阳能电池的酸性聚合物空穴收集层中添加弱碱的效果。将不同量的弱碱苯胺（AN）添加到聚（3,4-乙撑二氧噻吩）：聚（苯乙烯磺酸盐）（PEDOT:PSS）溶液中。添加苯胺的PEDOT:PSS溶液的酸度从pH = 1.74（AN = 0 mol%）逐渐降低至pH = 4.24（AN = 1.8 mol%）。PEDOT:PSS-AN薄膜的电导率随pH值变化不大，而面外与面内方向的电导率之比取决于溶液的pH值。即使所有具有PEDOT:PSS-AN层的器件的功率转换效率（PCE）均高于具有原始PEDOT:PSS层的器件，但在pH = 2.52时获得了最高的功率转换效率。原子力显微镜研究表明，随着pH值升高，PEDOT:PSS域的尺寸变小。在一个太阳条件下进行100小时光照的稳定性测试表明，具有PEDOT:PSS-AN层的器件的PCE衰减比具有原始PEDOT:PSS层的器件相对较慢。
